The invention relates to an arrangement of a plurality of oxygen breathing devices, in particular for providing oxygen to passenger or crew of an aircraft, each oxygen breathing device comprising an oxygen source, wherein oxygen is stored, in particular in chemically bound form or compressed form, an oxygen guiding device for guiding oxygen from the oxygen source to a person. A further aspect of the invention is an oxygen breathing device and a method for installing an emergency oxygen supply arrangement in an aircraft and a method of providing oxygen to passengers of an aircraft.
Arrangements of such oxygen breathing devices of the aforementioned type are used for a number of purposes where temporary or permanent supply of oxygen to a human person is necessary. A particular field of application of such oxygen breathing devices is the field of aircraft, wherein a pressure drop within an aircraft flying at high altitude may make it necessary to supply the passengers and the crew members with oxygen. Usually, an oxygen breathing device is provided for each crew member and passenger or a group thereof and is usually arranged above the passenger. In case of an emergency, such oxygen breathing device is activated, for example automatically by a cabin pressure monitoring system or manually by a crew member, whereafter an oxygen mask connected via a hose to an oxygen source falls from above the passenger downwards and can be used by the passenger. The flow of oxygen may be started automatically by activation of the system by the crew member or may be activated by a particular action undertaken by the passenger, e.g. by pulling the mask towards himself to thus activate the device by a pulling force transferred via the hose guiding the oxygen flow or an additional lanyard coupled to the oxygen mask.
A general problem associated with modern aircraft is the desire to provide an overall lightweight construction of the aircraft to reduce fuel consumption of the aircraft. It is to be understood that such lightweight construction may comprise a reduction of weight of structural components like wings of the aircraft but may also comprise a reduction of the weight of cabin interior elements, including passenger service units (PSU) and the like. It is an object of the invention to provide an oxygen breathing device allowing such lightweight construction of modern aircraft.
A still further object in design of modern aircraft is to allow efficient manufacturing and maintenance of the aircraft to reduce manufacturing and maintenance costs. It is an object of the invention to provide an oxygen breathing device allowing such reduced manufacturing and maintenance costs.
A particular problem associated with such oxygen breathing devices is the need to control the pressure and/or the flow of the oxygen provided to the person. If too little oxygen is provided to the person, this may cause severe damages to the person. Providing too much oxygen will require a large storage mass of the oxygen source and thus increase the total weight. Thus, usually a control unit is provided to control the flow and/or pressure of the oxygen. Such control unit may control the flow and/or pressure depending on the ambient pressure, the ambient oxygen content, the withdrawal of oxygen by the passenger or other input parameters.
Generally, it is known to drive such control unit using a drive energy supplied from an external energy source, in particular from the energy supply system of an aircraft in case where the oxygen breathing device is installed in such an aircraft. However, such approach of energy supply results in the need of extensive wiring and thus increased weight. Further, such wiring requires increased manufacturing efforts and thus tends to increase the manufacturing costs of aircraft.
A still further problem associated with such oxygen breathing devices lies in the fact that in modern aircraft a high variety of interior design is desired. This results in the need for interior cabin elements like oxygen breathing devices or passenger units which are adapted to be implemented into the aircraft at different locations and in different numbers. Further, it is desirable that the aircraft may be modified later without substantial constructive work in case that the interior design is changed. Prior art oxygen breathing devices require intensive preparational design work, commissioning, isolation and installation in the course of the initial manufacturing as well as later modification of an aircraft.
Still further it is a need for vital functions of an aircraft to provide safety against failure of single components. Often, this is achieved by redundant provision of such components which, however, further increases the weight, installation efforts and costs of systems providing such vital functions.